1. Field of the Invention
The present invention relates to a method for manufacturing a semiconductor apparatus, and more particularly to a method for manufacturing a semiconductor apparatus whereby a divisible multi-segment base material is formed and severed at predetermined cutting positions to obtain separate semiconductor apparatuses.
2. Description of the Related Art
A semiconductor apparatus is typically produced by severing a divisible multi-segment base material on which a multiplicity of semiconductor chips are mounted, at predetermined cutting positions.
With reference to FIGS. 8A through 8C, 9A, and 9B, a semiconductor apparatus of conventional design will be described below. FIGS. 8A through 8C are a plan view, a front view, and a bottom view, respectively, each showing a divisible multi-segment base material. FIG. 9A is an enlarged view showing a section D depicted in FIG. 8A. FIG. 9B is an enlarged view showing a section E depicted in FIG. 8C.
On a top-surface side of a substrate 90 is formed a wiring pattern (not shown) having mounted thereon a multiplicity of semiconductor chips (not shown). The wiring pattern has its surface sealed with resin 92, and also the semiconductor chips, together with the resin 92, are sealed with upper resin 92b. The wiring pattern and the semiconductor chips are electrically connected to each other by a gold wire (not shown).
On a back-surface side of the substrate 90 is formed a terminal portion 93 which is given plating so as to pair up with each of the semiconductor chips. In the terminal portion 93 is formed a terminal hole 931 to establish external electrical connection.
In this way, the divisible multi-segment base material 9 is obtained by forming the wiring pattern including a multiplicity of semiconductor chips on the substrate 90, followed by providing the terminal portion 93 thereon.
Next, with reference to FIGS. 8A through 8C, 9A, 9B, 10A, 10B, and 11A through 11C, a detailed description will be given below as to a process for dividing the above-described divisible multi-segment base material 9 into separate semiconductor apparatuses 91. FIGS. 10A and 10B are views each showing a process step for producing the semiconductor apparatus 91. FIGS. 11A through 11C are a plan view, a front view, and a bottom view, respectively, each showing the semiconductor apparatus 91 in finished form. Note that the xe2x80x9ccutting linexe2x80x9d shown in FIGS. 8A through 8C and FIG. 9A represents a cutting position at which the base material 9 is severed with a dicing machine provided with a blade 9a as shown in FIG. 9B.
The base material 9 shown in FIG. 10A is severed by moving the blade 9a, provided in the dicing machine, along the cutting line covering the terminal hole 931. By being severed along the cutting line, the divisible multi-segment base material 9 is cut into pieces, thus producing a multiplicity of semiconductor apparatuses 91 as shown in FIGS. 11A through 11C. Note that, as shown in FIGS. 10B, 11B, and 11C, the terminal hole 931 is left exposed along the cut surface of each of the separate semiconductor apparatuses 91.
However, a multiplicity of semiconductor apparatuses 91 thus produced suffer from the following drawbacks. Since the base material 9 is severed along the cutting line covering the terminal hole 93, the plating applied to the terminal hole 931 inconveniently comes off, resulting in burrs being developed. Occurrence of burrs in the terminal hole 931 leads to soldering failure, or causes short circuits between the terminals.
Furthermore, where the blade provided in the dicing machine is so designed as to perform 1-line cutting at one time (hereafter such a blade is referred to as the xe2x80x9csingle-type blade 9bxe2x80x9d), the number of cutting process steps is increased. As a method to reduce the number of cutting process steps, it is known to use a blade capable of cutting a plurality of lines at one time (hereafter such a blade is referred to as the xe2x80x9cmultiple-type blade 9cxe2x80x9d) for severing the base material 9. FIG. 12A is a view showing a state in which the base material 9 is being severed by the single-type blade 9b, and FIG. 12B is a view showing a state in which the base material 9 is being severed by the multiple-type blade 9c. As shown in FIGS. 12A and 12B, the multiple-type blade 9c is made 10 times as thick as the single-type blade 9b. For example, if the thickness of the single-type blade is assumed to be 0.1 to 0.2 mm, the multiple-type blade has a thickness of approximately 2 mm.
In the multiple-type blade 9c, though a plurality of lines can be cut at one time, a heavier load is required for cutting than in the case of performing cutting line by line. For this reason, the multiple-type blade 9c is made larger in thickness than the single-type blade 9b. Since a limitation is imposed on a range of selection of surface particle sizes for the multiple-type blade 9c, the multiple-type blade 9c is disadvantageous in terms of burr amount compared to the single-type blade 9b. 
To solve the above-described problems, an object of the invention is to provide a semiconductor apparatus manufacturing method by which burrs can be prevented from being produced along a cut surface of a terminal portion at the time of severing a base material.
The invention provides a semiconductor apparatus manufacturing method comprising the steps of:
forming a divisible multi-segment base material by mounting a multiplicity of semiconductor chips on a top-surface side of a substrate having a wiring pattern, followed by sealing the semiconductor chips with resin, further followed by attaching terminal portions each having a terminal hole to a back-surface side of the substrate; and
severing the base material at a position covering the terminal hole in such a way that the base material is divided into separate semiconductor apparatuses,
wherein, after formation of the base material, a filler is charged in each of the terminal holes, then the base material is severed after curing the filler, and lastly the filler filled in each of the terminal holes is removed.
According to the invention, after formation of the base material, a filler is charged in each of the terminal holes. Then, the base material is severed after curing the filler. With this method, even if a multiple-type blade is used, it is possible to prevent burrs from being produced along the cut surface of the terminal portion at the time of severing the base material. Moreover, the filler used to prevent occurrence of burrs is removed just after the severing, thus leaving no unnecessary components in the semiconductor apparatus.
In the invention, it is preferable that the filler contains a water-soluble substance.
According to the invention, the filler, containing a water-soluble substance, can be readily removed from the semiconductor apparatus with use of water.
In the invention, it is preferable that the water-soluble substance consists of barium hydroxide or polyvinyl alcohol.
In the invention, it is preferable that the filler contains an alkali-strippable substance.
According to the invention, the filler, containing an alkali-strippable substance, can be readily removed from the semiconductor apparatus with use of alkaline aqueous solution.
In the invention, it is preferable that the filler contains a thermosetting substance or an ultraviolet cure substance.
In the invention, it is preferable that the terminal hole is formed by drilling a plurality of continuous holes.
According to the invention, since the terminal hole is formed by drilling a plurality of continuous holes, its hole diameter is made larger than that of a terminal hole consisting of a single hole. As a result, even if the position at which the base material is severed is so located as to be deviated to the cutout-portion side with respect to a predetermined cutting position, the base material can be cut into separate semiconductor apparatuses without peeling off a plating applied to the terminal hole.
In the invention, it is preferable that the terminal hole is shaped like a slot.
According to the invention, the terminal hole is made larger in diameter than the above-mentioned terminal hole. Thus, even if the position at which the base material is severed is so located as to be deviated to the cutout-portion side with respect to a predetermined cutting position, the base material can be cut into separate semiconductor apparatuses without peeling off a plating applied to the terminal hole.
In the invention, it is preferable that the base material is severed in such a way that one part of the terminal hole removed as a result of severing the base material is made larger in volumetric capacity than the other part thereof remaining on the semiconductor apparatus.
According to the invention, one part of the terminal hole removed as a result of severing the base material is made larger in volumetric capacity than the other part thereof remaining on the semiconductor apparatus. Thus, even if the position at which the base material is severed is so located as to be deviated to the cutout-portion side with respect to a predetermined cutting position, the base material can be cut into separate semiconductor apparatuses without peeling off a plating applied to the terminal hole. This makes it possible to prevent burrs from being produced along the cut surface of the terminal portion at the time of severing the base material.
The invention further provides a semiconductor apparatus manufacturing method comprising the steps of:
forming a divisible multi-segment base material by mounting a multiplicity of semiconductor chips on a top-surface side of a substrate having a wiring pattern, followed by sealing the semiconductor chips with resin, further followed by attaching terminal portions each having a terminal hole to a back-surface side of the substrate; and
severing the base material at a position covering the terminal hole in such a way that the base material is divided into separate semiconductor apparatuses,
wherein, after formation of the base material, an electrically conductive substance is charged in each of the terminal holes, and the base material is severed after curing the electrically conductive substance.
The invention still further provides a semiconductor apparatus comprising:
a substrate;
a wiring pattern emplaced on a top-surface side of the substrate;
a semiconductor chip mounted on the top-surface side of the substrate;
resin for sealing the wiring pattern and the semiconductor chip; and
a terminal portion disposed on a back-surface side of the substrate, the terminal portion being given plating so as to pair up with the semiconductor chip,
wherein in the terminal portion is formed a terminal hole to establish external electrical connection,
and wherein the terminal hole is filled with a filler made of an electrically conductive substance.
According to the invention, after formation of the base material, an electrically conductive substance is charged in each of the terminal holes. Then, the base material is severed after curing the electrically conductive substance. Thus, it is possible to prevent burrs from being produced along the cut surface of the terminal portion at the time of severing the base material, and also to utilize the filler filled in the terminal hole to establish external connection.